The NF2 gene is the single most commonly mutated gene in benign tumors of the human nervous system. It is involved in the pathogenesis of virtually all schwannomas and many meningiomas (at least 50%) and ependymomas (Sainz et al., Hum. Mol. Genet. 3:885-891 (1994), Deprez et al., Am. J. Hum. Genet. 54:1022-1029 (1994), Rubio et al., Cancer Res. 54:45-47 (1994), Ruttledge et al, Nature Genet. 6:180-184 (1994), and Slavo et al., Cancer 64:243-247 (1995)). In addition to tumors, NF2 germline mutations also give rise to cataracts and retinal abnormalities such as hamartomas (Mautner et al., Neurosurgery 38:880-886 (1996)). The NF2 gene product is schwannomin (or merlin). Schwannomin is structurally similar to the ezrin-radixin-moesin (ERM) family of membrane-organizing proteins that link the plasma membrane and cytoskeleton (Rouleau et al., Nature 363:515-521 (1993) and Trofatter et al., Cell 72:791-800 (1993)). Schwannomin functions as a tumor suppressor, and as such is thought to have a role in a signal transduction pathway (Sainz et al., (1994), Huynh and Pulst, Oncogene 13:73-84 (1996), Tikoo et al., J. Biol. Chem. 269:23387-23390 (1994), and Twist et al., Hum. Mol. Genet. 3:147-151 (1994)). But other than its role in cell morphogenesis and adhesion (Huynh and Pulst (1996), supra), there is little additional knowledge of schwannomin function.
Therefore, there continues to be a need in the art for the discovery of additional proteins that interact with schwannomin, such as proteins that bind schwannomin in vivo, and especially a need for information serving to specifically identify and characterize such proteins in terms of their amino acid sequence. Moreover, to the extent that such molecules might form the basis for the development of therapeutic and diagnostic agents, it is essential that the DNA encoding them be elucidated. The present invention satisfies this need and provides related advantages as well.